“Large Band Gap Nanohybrid Materials”

Nicol Hall, Room 222, Beirut campus

Titled “Large Band Gap Nanohybrid Materials: Syntheses, Properties and Applications Studies,” the lecture will be given by Dr. Aurore Said.

Abstract by Dr. Aurore Said:
Elaborating nanostructured hybrid materials with novel physical properties has emerged as one of the most interesting research fields. Composed of inorganic matrix hosting organic dye molecules, these nanohybrids present a very promising approach for innovative nanomaterials by combining the properties of organic and inorganic materials in one nanoparticle. Hence, my Ph.D. studies consisted on designing dye-functionalized ZnO nanoparticles and studying their optical and morphological properties as well as the electronic interactions between inorganic ZnO and organic dye.

We produced nanohybrids based on ZnO spheres and rods via two routes: Femtosecond laser ablation in liquid medium and Solution-based chemical procedures. Spherical ZnO of few nanometers created by laser ablation reveal by photoluminescence the effect of quantum confinement due to size reduction. The chemically-synthesized ZnO rod-growth occurs through Oswald repining and Oriented attachment. These growth modes were monitored depending on synthesis time reaction and reactant nature by the High Resolution Transmission Electron Microscope (HRTEM). Optical properties of the hybrids strongly depend on ZnO shapes as well as on dye type and concentration. We were able to engineer the band gap of the small ZnO particles in the nanohybrid matrices simply upon varying the dye concentration. These hybrid nanoparticles are to be used in several applications; as the bi-photonic imagery in biology concerning for example the dynamics of a living cell, and as the photovoltaic industry via creation of dye functionalized-ZnO hybrid solar cells with relatively improved photon-to-current conversion efficiencies.

Event organizer: LAU’s School of Arts and Sciences – Natural Sciences Department